package com.tnovoselec.android.nfc.record;

import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import android.net.Uri;
import android.nfc.NdefRecord;

import com.google.common.base.Preconditions;
import com.google.common.collect.BiMap;
import com.google.common.collect.ImmutableBiMap;
import com.google.common.primitives.Bytes;
import com.tnovoselec.android.nfc.ParsedNdefRecord;

public class UriRecord implements ParsedNdefRecord {

	/**
	 * NFC Forum "URI Record Type Definition"
	 *
	 * This is a mapping of "URI Identifier Codes" to URI string prefixes,
	 * per section 3.2.2 of the NFC Forum URI Record Type Definition document.
	 */
	@SuppressWarnings("boxing")
	private static final BiMap<Byte, String> URI_PREFIX_MAP = ImmutableBiMap.<Byte, String> builder()
			.put((byte) 0x00, "")
			.put((byte) 0x01, "http://www.")
			.put((byte) 0x02, "https://www.")
			.put((byte) 0x03, "http://")
			.put((byte) 0x04, "https://")
			.put((byte) 0x05, "tel:")
			.put((byte) 0x06, "mailto:")
			.put((byte) 0x07, "ftp://anonymous:anonymous@")
			.put((byte) 0x08, "ftp://ftp.")
			.put((byte) 0x09, "ftps://")
			.put((byte) 0x0A, "sftp://")
			.put((byte) 0x0B, "smb://")
			.put((byte) 0x0C, "nfs://")
			.put((byte) 0x0D, "ftp://")
			.put((byte) 0x0E, "dav://")
			.put((byte) 0x0F, "news:")
			.put((byte) 0x10, "telnet://")
			.put((byte) 0x11, "imap:")
			.put((byte) 0x12, "rtsp://")
			.put((byte) 0x13, "urn:")
			.put((byte) 0x14, "pop:")
			.put((byte) 0x15, "sip:")
			.put((byte) 0x16, "sips:")
			.put((byte) 0x17, "tftp:")
			.put((byte) 0x18, "btspp://")
			.put((byte) 0x19, "btl2cap://")
			.put((byte) 0x1A, "btgoep://")
			.put((byte) 0x1B, "tcpobex://")
			.put((byte) 0x1C, "irdaobex://")
			.put((byte) 0x1D, "file://")
			.put((byte) 0x1E, "urn:epc:id:")
			.put((byte) 0x1F, "urn:epc:tag:")
			.put((byte) 0x20, "urn:epc:pat:")
			.put((byte) 0x21, "urn:epc:raw:")
			.put((byte) 0x22, "urn:epc:")
			.put((byte) 0x23, "urn:nfc:")
			.build();

	private final Uri mUri;
	private final List<String> resultList = new ArrayList<String>(1);

	private UriRecord(Uri uri) {
		mUri = Preconditions.checkNotNull(uri);
		resultList.add(mUri.toString());
	}

	public Uri getUri() {
		return mUri;
	}

	@Override
	public List<String> getContent() {
		return resultList;
	}

	/**
	 * Convert {@link android.nfc.NdefRecord} into a {@link android.net.Uri}.
	 * This will handle both TNF_WELL_KNOWN / RTD_URI and TNF_ABSOLUTE_URI.
	 *
	 * @throws IllegalArgumentException if the NdefRecord is not a record
	 *         containing a URI.
	 */
	public static UriRecord parse(NdefRecord record) {
		short tnf = record.getTnf();
		if (tnf == NdefRecord.TNF_WELL_KNOWN) {
			return UriRecord.parseWellKnown(record);
		} else if (tnf == NdefRecord.TNF_ABSOLUTE_URI) {
			return UriRecord.parseAbsolute(record);
		}

		throw new IllegalArgumentException("Unknown TNF " + tnf);
	}

	/** Parse and absolute URI record */
	private static UriRecord parseAbsolute(NdefRecord record) {
		byte[] payload = record.getPayload();
		Uri uri = Uri.parse(new String(payload, Charset.forName("UTF-8")));
		return new UriRecord(uri);
	}

	/** Parse an well known URI record */
	private static UriRecord parseWellKnown(NdefRecord record) {
		Preconditions.checkArgument(Arrays.equals(record.getType(), NdefRecord.RTD_URI));
		byte[] payload = record.getPayload();
		/*
		 * payload[0] contains the URI Identifier Code, per the
		 * NFC Forum "URI Record Type Definition" section 3.2.2.
		 *
		 * payload[1]...payload[payload.length - 1] contains the rest of
		 * the URI.
		 */
		@SuppressWarnings("boxing")
		String prefix = URI_PREFIX_MAP.get(payload[0]);
		byte[] fullUri = Bytes.concat(prefix.getBytes(Charset.forName("UTF-8")), Arrays.copyOfRange(payload, 1, payload.length));
		Uri uri = Uri.parse(new String(fullUri, Charset.forName("UTF-8")));
		return new UriRecord(uri);
	}

	public static boolean isUri(NdefRecord record) {
		try {
			UriRecord.parse(record);
			return true;
		} catch (IllegalArgumentException ex) {
			return false;
		}
	}
}